关键词: 菜薹, 氮, 铵转运蛋白（AMT）, 启动子, GUS

Abstract: In the present study，ammonium transporter gene BcAMT1;4 promoter sequence with upstream length of 2 086 bp for ATG was obtained from flowering Chinese cabbage（Brassica campestris L. ssp. chinensis var. utilis Tsen et Lee）using genomic walking. Bioinformatics analysis indicated that the promoter contains multiple cis-acting elements associated with light signals，hormone signals，stress response，and tissue-specific expression. To further analyze the promoter function of BcAMT1;4，a recombinant vector of BcAMT1;4 promoter and GUS was constructed and transformed into Arabidopsis by Agrobacterium tumefaciens. Analysis of T3 transgenic Arabidopsis tissues with GUS staining showed that GUS was mainly expressed in leaf，while expressed slightly in root，stem，and flower. Also，the activity of BcAMT1;4 promoter was affected by nitrogen source forms in Arabidopsis. Nitrogen starvation induced the GUS activity in transgenic Arabidopsis，however，the GUS activity was inhibited by 0.25 mmol ? L-1 NO3-，NH4+，or NH4NO3 treatment. In conclusion，the results showed that BcAMT1;4 might play an important role in regulating ammonium nutrient in leaf of flowering Chinese cabbage.

Key words: flowering Chinese cabbage, nitrogen, ammonium transporter, promoter, GUS